Chapter 6: Materials Flashcards
What is Elastic Deformation?
Elastic Deformation is when an object changes in shape when a tensile or compressive force is applied to it and returns to its original length when the force is removed.
What is Plastic Deformation?
Plastic Deformation is defined as the permanent change in shape of an object when a tensile or compressive force is applied to it, and will not return to its original length and size when the force is removed.
What is the Elastic Region on a Force-Extension Graph?
The Elastic Region is the region where an object will experience elastic deformation given that the elastic limit is not exceeded. This can be beyond the limit of proportionality but not the elastic limit.
What is Hooke’s Law, and its equation?
Hooke’s Law states that the extension of a spring is directly proportional to the force applied to it given that the elastic limit is not exceeded.
The Equation for Hooke’s Law is:
Force = Spring Constant x Extension
What is the definition of Spring/Force Constant?
The Spring or Force Constant is a measure of stiffness of the object that shows the amount of force needed to extend a spring by a given length.
What is the Gradient in a Force-Extension Graph?
The Gradient of a Force-Extension Graph is the Spring Constant.
How can you investigate Hooke’s Law?
When can the work done on a material be fully recovered?
The work done or energy transferred on a material can be fully recovered when the load is removed and the material does not go beyond its elastic limit.
What is the equation that links Work Done, Force and Extension?
The Equation that links Work Done, Force and Extension is:
Work Done = Force x Extension
What is the area underneath a Force-Extension Graph?
The area underneath a Force-Extension Graph is the Work Done.
What is the equation to calculate the Elastic Potential Energy?
The Equation to calculate the Elastic Potential Energy is:
E = ½Fx, Energy = ½ x Force x Extension
What is the equation to calculate the Elastic Potential Energy if a spring obeys Hooke’s Law?
If a spring obeys Hooke’s Law, the equation to calculate EPE is:
E = ½kx² , Energy = ½ x Spring Constant x Extension²
This is derived by substituting ‘F’ with ‘kx’, and this equation can be rearranged.
